Help with oil pump problem on 1969 SBC 350 Engine

[jcloud6]

I picked up this 1969 SBC 350 from a guy for less than a hundred bucks. According to the engine suffix code this came with 300 factory horse power. He had block dipped, bored .30 over, new freeze plugs, cam bearing, pistons, crank, cam and oil pump. He sold this engine because he cannot figure out why the oil is not being pumped up to the valve train.

Q. Could the cam bearing be install wrong.
Q. Could there be a difference in oil pump/shaft
Q. Could there be a difference in distributors
Q How should I trouble shoot this to determine the problem